Deprecate older go versions, .godir & Godeps file
Deprecate older go versions, .godir & Godeps file

heroku/heroku-buildpack-go,michael-go/heroku-buildpack-go,venicegeo/go-pdal-buildpack,michael-go/heroku-buildpack-go,heroku/heroku-buildpack-go,venicegeo/go-pdal-buildpack,titanous/heroku-buildpack-go,loafoe/go-buildpack,enkoder/heroku-buildpack-go,cloudfoundry/go-buildpack,venicegeo/go-pdal-buildpack,cloudfoundry/go-buildpack,loafoe/go-buildpack,cloudfoundry/go-buildpack,loafoe/go-buildpack